In a high side fixed vane or rolling piston rotary compressor, a vane reciprocates in a vane slot formed in the cylinder as the vane acts as a cam follower relative to the eccentric piston. The vane divides a crescent shaped chamber formed by the piston and cylinder into a suction chamber and a discharge chamber. Hot, compressed gas passes from the discharge chamber, through a muffler into the interior of the shell or casing in a pulsed flow. The pulsed flow tends to cause vibrations. Conventionally the crankcase is placed in the shell with a clearance and then plug welded at several discrete points. As a result, the shell has relatively large areas with strong sound radiating characteristics acted on by the pressure pulsations of the pulsed flow.